Antioxidant Properties and Chemical Characteristics of Cow-s Milk Kefir Enriched with Ginger Extract (Zingeber officinalle)
Putri Dian Wulansari*1 and Novia Rahayu2
Department of Animal Science, Faculty of Agriculture, Universitas Perjuangan Tasikmalaya, INDONESIA.
Abstract
Background: Kefir is currently much in demand and trusted by the public because it has healthy benefits, one of which is to replace the use of synthetic antioxidants as free radical scavengers. Fermented milk is a good antioxidant vehicle, the addition of microorganism during fermentation can increase antioxidant activity (1). Another source of natural antioxidants is by adding isolation from natural sources of antioxidants (2). Ginger (Zingeber officinale) is an herbal plant that has antioxidant activity that has long been used as an alternative to traditional medicine and is found in Indonesia. However, no references have been found yet about the functional component of ginger extract is added in the fermentation process of cow-s milk kefir on the antioxidant activity and chemical characteristics it produces. Aims: This research was conducted in an effort to characterize the antioxidant activity and chemical characteristics of cow,s milk kefir enriched by ginger extract. Materials and Methods: Fresh Cow-s milk was obtained from As-Salam Breeding Farm in Tasikmalaya; grain kefir from Milky Way in Bogor; and ginger from traditional market in Tasikmalaya. The research employed a Completely Randomized Design (CRD). This study consisted of 5 treatment (each repeated 5 times) with an interval of giving ginger extract 0; 0.5; 1.0; 1.5; 2%. Ginger extract was used methode (3). The process of making kefir uses the modified methode (4). The milk was transported in a cold condition, and was pasteurized at 72oC for 15 second, then was cooled to 28oC than inoculated with ginger extract according to the treatment and grain kefir as much as 10%, and incubated for 24 hours to allow fermentation process. Milk kefir was separated from kefir grains by using a fine plastic strainer and ready for analysis. The data obtained were analysed using Two Way Anova with SPSS software version 17 with a confidence level of 95%, and further tests using the Least Significant Difference Test (5). Results: The parameter measured in this study were antioxidant activity (DPPH and total polyphenol levels) and chemical characteristics (alcohol content, free fatty acids, lactic acid levels and pH). The result showed that the addition of ginger extract had no effect on alcohol levels, free fatty acids, lactid acid levels, and pH but were able to increase antioxidant activity (DPPH) and total polyphenol levels. The average alcohol content, free fatty acids, lactid acid levels and pH in this study were 1.42 g/dl, 0.5503 mg/KOH, 1.0005% and 4.42 fulfilling kefir quality requirements set by Codex Stan 243-2003. The more addition of ginger extract (0-2%) to the manufacture of kefir, the higer the antioxidant activity (DPPH) and the total phenolics levels. Conclusion: Conclusion on this study is the addition of ginger extract in fermentation cow-s milk kefir can increase antioxidant activity and total polyphenol levels, without affecting its chemical characteristics.
Keywords: Antioxidant; Chemical Characteristics; Cow-s Milk; Ginger Extract; Kefir; and Total Phenol.
Topic: Environmentally Sustainable Agriculture